There have been many efforts in the prior art to develop alternatives to the pull-tab container lids generally used for manually opened beverage containers. While pull-tab lids make it unnecessary to use a separate opener, the tabs themselves become separated from the containers when they are used, creating a disposal problem. Because of their sharp edges, the tabs may also cause injury if they are not properly pulled.
One alternative to the pull-tab container lid has been the so-called pop-in lid, which generally has a button-shaped portion formed with a peripheral scoring. To open, the user presses downwardly on the button-shaped portion, rupturing the lid along the scoring line to permit the portion to be bent inwardly. While this alternative solves the disposal problem, it creates a safety problem of its own, as the user may cut his finger on the ruptured scoring line at some stage of the opening process. Both of the lids discussed hereinabove permit the pressure of the contents to escape upwardly as the can is opened and possibly into the user's face.